Phosphoro reactions with

Preparation of enolphosphates. The reagent is used in ether solution to convert A4-cholestene-3-one (I) into the enol form for reaction with diethyl phosphoro-chloridatc and tricthylamine to give the phosphate ester (3). Reaction with lithium and ethylamine, and treatment with t-butyl alcohol then affords 5-methyl-A -coprostene (4). 

Schmidt and Wong have developed 2-diethyl and 2-dibenzyl phosphite derivatives of NeuSAc 80 [86] and 81 [87], individually. Both of the 2-phosphite derivatives can be prepared from a 2-hydroxy derivative of NeuSAc 79 by the reaction with ClP(OEt)2 in the presence of Hiinig s base, and by the reaction of A,iV-diethyl phosphoro amidite and tetrazole, respectively (O Scheme 24). 

The efficient syntheses of 2 -deoxyribonucleoside 3 -0- and 5 -0-phosphoro-dithioates 11 12 has been described.In each case phosphorylation of either the 3 -0- or 5 -0-protected nucleoside with 2-chloro-l,3,2-dithiaphospholane, followed by oxidation with sulfur gives the 2-thio-l,3,2-dithiaphospholane 13. Compound 13, upon DBU-catalysed reaction with 2-cyanoethanol gives 14 via loss of episulfide. Treatment with aqueous ammonia afforded the desired compounds 11 12. 

Compounds of this type may be prepared also by reaction of the respective mercaptan with phosphorus trichloride, treating the resulting dialkyl phosphoro-chloridothioite with alcohol and subsequent oxidation with an oxidant such as hydrogen peroxide (Wilson, 1966). 

Lithium enolates, formation, 52,109 preparation and alkylation, 52, 39 reaction with diethyl phosphoro-chloridate, 52,109... 

Reactions with phosphoro-l-imidazolidates Subst. carboxylic acid amides from carboxylic acids... 

Various S-nucleophiles are allylated. Allylic acetates or carbonates react with thiols or trimethylsilyl sulfide (353) to give the allylic sulfide 354[222], Allyl sulfides are prepared by Pd-catalyzed allylic rearrangement of the dithio-carbonate 355 with elimination of COS under mild conditions. The benzyl alkyl sulfide 357 can be prepared from the dithiocarbonate 356 at 65 C[223,224], The allyl aryl sufide 359 is prepared by the reaction of an allylic carbonate with the aromatic thiol 358 by use of dppb under neutral condi-tions[225]. The O-allyl phosphoro- or phosphonothionate 360 undergoes the thiono thiolo allylic rearrangement (from 0-allyl to S -allyl rearrangement) to afford 361 and 362 at 130 C[226],... 

In this scheme, EOH is the enzyme, IX is the inhibitor (either a carbamate or an organophosphate). EOH(IX) is analogous to the Michaelis Menton comploc seen with the substrate reaction. EOI is the acyl-enzyme intermediate for carbamates or a phosphoro-enzyme intermediate for the organophosphates. The equilibrium constant for this reaction (K ) is defined as k /k and the phosphorylation or carbamylation constant is defined as k2- In this study 42)y ANTX-A(S) was found to be more specific for AChE than BUChE. The double reciprocal and Dixon plot of the inhibition of electric eel AChE indicated that the toxin is a non-competitive inhibitor decreases, k remains unchanged) (Figure 2). 

Dimethyl chlorophosphite, (CH30)2PC1 (1). This dimethyl ester of phosphoro-chloridous acid is obtained by reaction of (CH30)3P with PC13 in [(CH3)2N]3PO as solvent (74.5% yield).1... 

Reaction of esterases with radioactive di isopropyl phosphoro-... 

The rate of reaction of phosphorus oxychloride with phenols to produce triaryl phosphates is increased by the addition of quaternary ammonium salts and the reaction temperature can be reduced without loss of overall yield [1,2]. The analogous reaction between phenoxide anions and thiophosphoryl chloride produces aryl phosphoro-dichloridothoates [3]. As with the acylation of enolizable (3-dicarbonyl compounds (3.3.12), phosphorylation leads to the predominant formation of the E-O-phos-phoryiated derivatives [4,5]. 

The reaction has sometimes been called the "phosphoro-clastic reaction" because the product acetyl-CoA usually reacts further with inorganic phosphate to form acetyl phosphate (see Fig. 15-16). The latter can then transfer its phospho group to ADP to form ATP. 

Traces of an optically active anhydroribitol and its phosphates are produced when some teichoic acids are hydrolyzed with alkali.66 67 No anhydroribitol is formed by similar treatment of ribitol, its 1-, 2-, or 3-phosphates, or ribitol 1,5-diphosphate.68 However, small proportions of anhydroribitol and its phosphates are produced by the action of alkali on a synthetic poly (ribitol phosphate) prepared by the action of diphenyl phosphoro-chloridate oil 3,4-O-isopropylideneribitol l-phosphate and 2-phosphate.68 This observation suggests that 1,4-anhydroribitol (13) or its derivatives (15) are produced by fission of a phosphodiester, for example (14), in the manner indicated in Fig. 3, and that this reaction occurs together... 

We wish to report that on treatment with a solution of sodium hydroxide in aqueous dioxan, (A) was converted by endocyclic P-0 cleavage into (C). Alkylation of (C) with methyl iodide followed by acetylation with acetic anhydride/pyridine resulted in (D), which reacted with a dilute solution of anhydrous hydrogen chloride in methanol to give R-(+)-ethyl 0,S-dimethyl phosphoro-thioate (E). Since both S-alkylation and O-acetylation involve no reaction at phosphorus, and available evidence suggests that under the conditions used acid catalysed P-N cleavage in N,N-dialkyl phosphoramidothioates occurs with inversion (6), the observed sequence (Scheme 2) implies that endocyclic P-0 cleavage occurs with retention of configuration at phosphorus. 

It has been demonstrated that the reaction of a lactam enolate with diethyl phosphoro-chloridate and subsequent oxidation is an equally attractive method for transformation of different N-farnesyl lactams and imides (307) to the corresponding a-phosphono lactams (308) (Scheme... 

---